Remember when actor Jeremy Piven caused a media storm after he came down with a severe case of exhaustion just from eating sushi? Yikes. Well, now sushi lovers have something else to be worried about.

It turns out that the hottest L.A.-based sushi restaurants are purposely deceiving consumers about their menu items.

In a recent four-year study conducted by researchers at the University of California and Loyola Marymount University, almost half of the fish ordered from over 25 of the top-rated sushi restaurants in the city are mislabeled.

The study comes as quite a shock, especially since looks are everything in L.A., and people are very careful about what they eat.

“Half of what we’re buying isn’t what we think it is,” the study’s lead author, Paul Barber said. “Fish fraud could be accidental, but I suspect that in some cases the mislabeling is very much intentional, though it’s hard to know where in the supply chain it begins.”

Of all the different types of sushi, halibut, yellowfin tuna and red snapper were swapped out for cheaper varieties of fish most often (like flounder), while bluefin tuna and salmon were mislabeled the least. You know that health-conscious friend of yours who only ever orders salmon and tuna sashimi? Looks like they were on to something.

Now the fear is that Japanese restaurants a little closer to home may be copying their friends south of the border. In Vancouver, where more restaurants sell sushi than lattes, foodies are thinking twice about ordering their favorite fish.